Abdelbaset Ali Mohmed Al Megrahi, 58, was freed from Greenock Prison last August on compassionate grounds – with supposedly just three months left to live because of cancer – eight years into a minimum 27-year ­sentence.

But yesterday the Scottish Tories, fierce critics of the decision to release Britain’s biggest mass murderer, demanded that the SNP Government publish all the medical evidence that led to Justice Secretary Kenny ­MacAskill sending the bomber home to a hero’s welcome in Libya.

Mr Salmond said he did not regret Megrahi’s release and added: “You can only take a decision based on information at the time. It’s not unheard of for people who have been released on compassionate grounds to live longer than the three months specified.”

Megrahi is the only person convicted of the Lockerbie atrocity, which killed 270 people on December 21, 1988. He is with his family in Tripoli. Mr MacAskill said: Dealing with cancer is not an exact science.

“If you’re far from home and your family and you’re in prison in Scotland, then you can turn your face to the wall. If you’re at home and being treated, you may live longer. What is undeniable is that he is terminally ill with prostate cancer, he has been released to Libya and he’s going to die very soon.”

But Scottish Tory leader Annabel Goldie insisted: “Kenny MacAskill and the SNP should take responsibility for the decision they made. If he hadn’t been released, there would be no furore now. A year on the SNP has still not proved its decision was just and sound.

“Indeed, they now claim the three-month prognosis only applied if Mr Megrahi remained in prison, a new line. They have to publish all the medical evidence they received last summer. The release is a matter of public interest and public confidence in the devolved Scottish justice system.

“To hide behind the wishes of Mr Megrahi’s family as a reason to keep medical reports secret is ridiculous and shameful. Publish and end speculation now. The solution is in their hands.” A Scottish Government spokesman said: “Like any other medical patient treated in Scotland, Mr Megrahi is entitled to confidentiality. His family have insisted his medical details are not released into the public domain and we must respect those wishes.

“We have already published all ­relevant documentation surrounding the decision for his release. The US ­authorities have also requested any communications between them and us remain confidential.” In a separate development yesterday Mr Salmond wrote to Senator John Kerry, chairman of the US Senate ­Committee on Foreign Relations, making clear the Scottish Government didn’t receive any representations from BP in relation to the bomber’s release.

Mr Salmond wrote: “I can say unequivocally the Scottish Government has never, at any point, received any representations from BP in relation to Megrahi.

“We had no submissions or lobbying of any kind, either oral or written, and to my knowledge, the subject was never raised by any BP representative to any Scottish Government Minister.”